ICU patients who receive high levels of oxygen therapy are no better off than those given conventional oxygen regimens, a ground-breaking Australian study suggests.

The new findings,  published in the New England Journal of Medicine, are likely to inform how oxygen is administered to millions of patients in ICU wards across the world, the researchers say.

In the multicentre Australian and New Zealand trial, 965 adult patients across 21 ICUs were randomly assigned to either usual or conservative oxygen therapy to determine whether higher oxygen levels resulted in better survival rates and recovery outcomes.

Those in the conservative therapy group had their oxygen saturation tightly controlled between 91-97%, and the fraction of inspired oxygen was kept below 0.21.